This invention relates to gramophone equipment and particularly concerns tone arm control in gramophone equipment.
Tone arm control is disclosed in Stimler U.S. Pat. No. 2,952,464 and further details are disclosed in Nakagiri et al U.S. Pat. No. 3,368,080.
Stimler and Nakagiri et al propose the use of photoelectric scanning to sense record reflectivity and hence the number of bands of low groove density (i.e. of relatively high reflectivity). Stimler proposes that the signal from the scanning means be processed by using the signal to step a uniselector the steps of which are connected to the contacts of a multiposition switch operable manually to make a selection, this switch constituting a store for the selection. However, this solution is disadvantageous commercially because only a single selection can be made, because a manual rejection operation must be made to discontinue playing at the end of a track and make a new selection, and because this electromechanical solution takes up a significant amount of space and might tend to increase the size of gramophone equipment. Nakagiri et al is concerned merely with attempting to overcome optical problems inherent in Stimler and arising because of the varied nature of records currently on the market.